Red yeast rice is a traditional food consumed throughout Asia. Its food value and medicinal value is believed to date back more than a thousand years, with the first documentation of its use recorded in 800 A.D. Red yeast rice is sold in jars at Asian markets as pasteurized wet aggregate, whole dried grains, or as ground powder. It was a commonly used red food colouring in East Asian and Chinese cuisine prior to the discovery of chemical food coloring. It has also been used in Chinese herbal medicine.
The yeast Monascus isolated from red yeast rice first became known in Western society through the work of Dutch scientists, who noted its use by local populations in Java in 1884. A species isolated from red Koji or Honqu (as red rice yeast is known in East Asia) was named Monascus Purpureus Went in 1895, in recognition of the purple coloration. Today there are more than 30 Monascus strains on deposit with the American Type Culture Collection.
The traditional method of making red yeast rice is to ferment the yeast naturally on a bed of cooked non-glutinous whole rice kernels. Extracts from red yeast rice contain starch, sterols, isoflavones, and monounsaturated fatty acids, and other compounds. Depending on the Monascus strains used and fermentation conditions, it may contain polyketides called monacolins. These monacolins are believed to account for the majority of the cholesterol-lowering activity of the yeast. One of these, “Monacolin K,” is a potent inhibitor of HMG-CoA reductase, and is also known as Lovastatin™, a commonly prescribed lipid-lowering drug.
Dengue fever and dengue hemorrhagic fever are caused by one of four closely related, but antigenically distinct, virus serotypes (DEN-1, DEN-2, DEN-3, and DEN-4), of the genus Flavivirus. Infection with one of these serotypes provides immunity to only that serotype for life, so persons living in a dengue-endemic area can have more than one dengue infection during their lifetime. Dengue fever and dengue hemorrhagic fever are primarily diseases of tropical and sub tropical areas, and the four different dengue serotypes are maintained in a cycle that involves humans and the Aedes mosquito. However, Aedes aegypti, a domestic, day-biting mosquito that prefers to feed on humans, is the most common Aedes species.
In 2005, dengue is the most important mosquito-borne viral disease affecting humans; its global distribution is comparable to that of malaria, and an estimated 2.5 billion people live in areas at risk for epidemic transmission. Each year, tens of millions of cases of dengue fever occur and, depending on the year, up to hundreds of thousands of cases of dengue hemorrhagic fever.
Dengue fever usually starts suddenly with a high fever, rash, severe headache, pain behind the eyes, and muscle and joint pain. The severity of the joint pain has given dengue the name “breakbone fever.” Nausea, vomiting, and loss of appetite are common. A rash usually appears 3 to 4 days after the start of the fever. The illness can last up to 10 days, but complete recovery can take as long as a month. Older children and adults are usually sicker than young children.
Most dengue infections result in relatively mild illness, but some can progress to dengue hemorrhagic fever. With dengue hemorrhagic fever, the blood vessels start to leak and cause bleeding from the nose, mouth, and gums. Bruising can be a sign of bleeding inside the body. Without prompt treatment, the blood vessels can collapse, causing shock (dengue shock syndrome). The case-fatality rate of dengue hemorrhagic fever in most countries is about 5%, but this can be reduced to less than 1% with proper treatment. Most fatal cases are among children and young adults.
Because dengue is caused by a virus, there is no specific medicine or antibiotic to treat it. For typical dengue, the treatment is purely concerned with relief of the symptoms (symptomatic). Rest and fluid intake for adequate hydration is important.
No dengue vaccine is available. Recently, however, attenuated candidate vaccine viruses have been developed. Efficacy trials in human volunteers have yet to be initiated. Research is also being conducted to develop second-generation recombinant vaccine viruses. Therefore, an effective dengue vaccine for public use will not be available for 5 to 10 years.
Prospects for reversing the recent trend of increased epidemic activity and geographic expansion of dengue are not promising. New dengue virus strains and serotypes will likely continue to be introduced into many areas where the population densities of Ae. aegypti are at high levels. Hence, there is a need for finding new method of preventing and treating diseases caused by the dengue virus.